Probing a device

ABSTRACT

An electronic device is moved into a first position such that terminals of the electronic device are adjacent probes for making electrical contact with the terminals. The electronic device is then moved horizontally or diagonally such that the terminals contact the probes. Test data are then communicated to and from the electronic device through the probes.

FIELD OF THE INVENTION

This invention relates generally to probing a device.

BACKGROUND

Although the present invention is generally applicable to probing anydevice, the present invention is particularly suited for probing anintegrated circuit to test the circuit. As is known, integrated circuitsare typically manufactured as a plurality of dies on a semiconductorwafer. FIG. 1 illustrates a typical test system 100 for testing such asemiconductor wafer 124. The exemplary test system shown in FIG. 1,includes a tester 102, a test head 118, a probe card 106, and a prober120.

A semiconductor wafer 124 is placed on a chuck (also commonly referredto as a stage) 114, which typically is capable of movement in the “x,”“y,” and “z” directions. The chuck 114 may also be capable of beingrotated (e.g., in the “θ” direction) and tilted and may be furthercapable of other motions as well. Once the semiconductor wafer 124 isplaced on the chuck 114, the chuck is typically moved in the “x,” “y,”and/or “θ” directions so that terminals on the dies (not shown) of thewafer 124 align with probes 108 on the probe card 106. The chuck 114then typically moves the wafer 124 upward in the “z” direction, bringingthe terminals into contact with the probes 108. One or more cameras 122may aid in aligning the terminals and the probes and determining contactbetween the probes 108 and the terminals.

Once the terminals of the dies (not shown) are in contact with theprobes 108, a tester 102, which may be a computer, generates test data.The test data is communicated through one or more communication links104 to a test head 118. The test data is communicated from the test head118 through interconnections 116 (e.g., pogo pins) to the probe card 106and finally to the terminals of the dies (not shown) through probes 108.Response data generated by the dies are communicated in reversedirection from the probes 108, through the probe card 106, throughinterconnections 116, through the probe head 118, through acommunication link 104, to the tester 102.

FIGS. 2A-2C illustrate movement of the wafer 124 into contact with theprobe card 106. As mentioned above and shown in FIG. 2A, terminals 220of one or more dies 202 a of wafer 124 are aligned with probes 108 ofthe probe card 106. The chuck 114 them moves the wafer upward such thatthe terminals 220 of the die 202 a contact probes 108, as shown in FIG.2B. As shown in FIG. 2C, the chuck 114 typically moves the wafer 124beyond first contact with the terminals 220. (Movement beyond firstcontact is often referred to as “over travel.”) This typicallycompresses the probes 108. The resulting spring force exerted by theprobes 108 against the terminals 220 helps to create a reasonably lowresistance electrical connection between the probes and the terminals.In addition, the probes 108 often wipe across the surface of theterminals 220 as the probes are being compressed. The wiping actiontends to cause the tips of the probes 108 to break through any oxide orother build up on the terminals 220, again helping to create areasonably low resistance electrical connection between the probes andthe terminals.

As might be expected, compression of the probe 108 and the wiping actioninduce forces and stresses in the probe, which may break, damage, orreduce the useful life of a probe 108. In addition, the force exerted bythe probe 108 against the terminal 220 may damage the terminal 220and/or the wafer 124. A wafer 124 comprising material with a low “k”dielectric may be particularly susceptible to such damage. Generallyspeaking, the greater the friction between a probe 108 and a terminal220, the greater such forces and stresses are likely to be. Indeed, itis possible for frictional forces to prematurely stop the wiping of theprobe 108 tip across the terminal 220. This may happen, for example, ifthe probe 108 tip digs too deeply into the terminal 220 or if the probetip gets caught in an irregularity on the surface of the terminal. Ifthe probe 108 tip stops its wiping motion prematurely, the forces andstresses that build up on the probe may become particularly large (andtherefore particularly likely to cause damage to the probe, terminal,and/or wafer). Although a probe 108 may dig into any type of terminal204, a probe 108 is particularly susceptible to digging into a terminalmade of a soft material (e.g., solder ball or aluminum terminals) or aterminal with a rough surface (e.g., copper terminals). Embodiments ofthe present invention, among other things, may reduce stresses in aprobe and forces exerted by and against a probe. One nonlimitingadvantage of the invention is in reducing or replacing the verticalcomponent of relative movement between the probe and the terminal asthey are brought into contact by a wiping action, which reduces theforces on and stresses in the probe.

SUMMARY

This invention relates generally to probing a device and is particularlyapplicable to probing an electronic device (e.g., a semiconductordevice) to test the device. In one embodiment, an electronic device ismoved into a first position such that terminals of the electronic deviceare adjacent probes for making electrical contact with the terminals.The electronic device is then moved horizontally or diagonally such thatthe terminals contact the probes.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an exemplary prior art semiconductor test system.

FIGS. 2A-2C illustrate operation of a portion of the exemplary testsystem illustrated in FIG. 1.

FIG. 3 illustrates an exemplary test system.

FIG. 4 illustrates an exemplary process for probing a semiconductordevice.

FIGS. 5A-5C illustrate an exemplary application of the process of FIG.4.

FIGS. 6A-6C illustrate another exemplary application of the process ofFIG. 4.

FIG. 7 illustrates a modified exemplary application of the process ofFIG. 4.

FIGS. 8A and 8B illustrate another exemplary process for probing asemiconductor device.

FIGS. 9A and 9B illustrate yet another exemplary process for probing asemiconductor device.

FIGS. 10A and 10B illustrate an exemplary probe with multiple tips.

FIGS. 11A-11C illustrate exemplary positioning and movement of a probewith respect to multiple terminals.

FIG. 12 illustrates another exemplary test system.

FIGS. 13A-13C illustrate still another exemplary process for probing asemiconductor device.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The present invention relates to probing a device. This specificationdescribes exemplary embodiments and applications of the invention. Theinvention, however, is not limited to these exemplary embodiments andapplications or to the manner in which the exemplary embodiments andapplications operate or are described herein.

FIG. 3 illustrates an exemplary semiconductor test system 400. Testsystem 400 is exemplary only; other systems in which any type of probeis brought into contact with another device may be used. Nonexclusiveexamples of such systems include sockets for testing packaged orunpackaged semiconductor devices, or any type of test system in which asemiconductor device (packaged or unpackaged, singulated orunsingulated, diced or in wafer form) is probed. As another example, anysystem in which a probe is brought into contact with some sort ofsurface may be used. Of course, even if a semiconductor wafer testsystem is used, a semiconductor test system that is different than theexemplary test system 400 shown in FIG. 3 may be used. Nonlimitingexamples of electronic devices that may be tested include asemiconductor wafer, a semiconductor device, a package for asemiconductor device, a package for a plurality of semiconductordevices, a semiconductor die singulated from a semiconductor wafer, aplurality of semiconductor dies singulated from a semiconductor wafer, aprinted circuit board, and a wired ceramic substrate such as a spacetransformer. Another example is an electronic system comprising printedwiring layers, semiconductor devices, and connections between the wiringlayers and the semiconductor devices.

The exemplary semiconductor test system 400 illustrated in FIG. 3 isgenerally similar to the test system 100 shown in FIG. 1. That is,exemplary test system 400 includes a tester 402, one or morecommunication links 404, a prober 420, a test head 418, a probe card406, and interconnections 416 between the probe card and the test head,all of which may be generally similar to like elements as described withrespect to FIG. 1. The prober 420 may include a variety of elements suchas one or more cameras 422, which may be generally similar to thecameras 122 illustrated in FIG. 1.

Probe card 406 may be any type of probe card, including withoutlimitation a probe card 406 assembly as illustrated in U.S. Pat. No.5,974,662 or 6,509,751, both of which are incorporated by referenceherein in their entirety. Probes 408 may be any type of probes,including without limitation needle probes, buckling beam probes (e.g.,“COBRA” probes), bumps, posts, and spring probes. Nonexclusive examplesof spring probes include the spring contacts described in U.S. Pat. Nos.5,917,707, 6,255,126, 6,475,822, and 6,491,968; and U.S. PatentApplication Publication No. 2001/0044225 A1 and U.S. Patent ApplicationPublication No. 2001/0012739 A1. The foregoing patents and patentapplication are incorporated herein by reference in their entirety.

As shown in FIG. 3, the test system 400 also includes a controller 430for controlling movement of the chuck 414. For convenience (not by wayof limitation), directions in FIG. 3 are identified using an “x,” “y,”“z,” and “θ” coordinate system in which the “z” direction is thevertical direction (up or down) with respect to FIG. 3, the “x”direction is horizontally into or out of the page, the “y” direction isalso horizontal but to the right or left in FIG. 3, and “θ” is rotation.

The controller 430 may be any suitable controller for controllingmovement of the chuck 414. The controller 430 illustrated in FIG. 3 is amicroprocessor based controller. As shown, controller 430 includes adigital memory 432, a microprocessor 434, input/output electronics 436,and input/output port 438. The digital memory 432 may be any type ofmemory including an electronic memory, an optical memory, a magneticmemory, or some combination of the foregoing. As just two examples,digital memory 432 may be a read only memory, or digital memory 432 maybe a combination of a magnetic or optical disk and a random accessmemory. Microprocessor 434 executes instructions (e.g., software ormicrocode) stored in digital memory 432, and input/output electronics436 controls input and output of electrical signals into and out ofcontroller 430. Input data is received and output data is output viaport 438. Control signals for controlling movement of chuck 414 areamong data output via port 438. Such software or microcode may beconfigured to control the chuck movements described herein.

Controller 430 may be a stand alone entity as illustrated in FIG. 3.Alternatively, controller 430 may be contained within the prober 420.Indeed, a typical prober includes a microprocessor based control systemfor moving chuck 414, and controller 430 may comprise such an existingcontrol system configured with software or microcode to execute thechuck movements described herein. Of course, the controller 430 may belocated in other elements of system 400 or may be distributed among oneor more elements of system 400.

The controller 430, however, need not be microprocessor based. Indeed,any system for controlling movements of chuck 414 may be used. In fact,controller 430 may comprise manual mechanisms by which an operatormanually moves the chuck 414.

FIGS. 4 and 5A-5C illustrates an exemplary process for testingsemiconductor wafers 424 utilizing the test system 400 shown in FIG. 3.As shown in FIGS. 4 and 5A, a wafer 424 to be tested is placed on thechuck 414 (step 502). As shown in FIGS. 4 and 5B, the chuck 414 thenmoves the wafer 424 such that terminals 620 on the wafer 424 are broughtinto a position laterally adjacent tips 636 of probes 408 (step 504). Asone example, and as shown in FIG. 5B, the terminals 636 may bepositioned such that the tips 636 of probes 408 do not touch wafer 424but are nevertheless positioned below the top surfaces of terminals 620.Of course, the wafer 424 could alternatively be held stationary and theprobes 408 moved, or both the wafer 424 and the probes 408 could bemoved. In the system shown in FIG. 3, software running in controller 430may issue commands via I/O port 438 to control the movement of chuck414.

Cameras 422 may be used to determine the position of the tips 636 of theprobes 408 with respect to the wafer 424. Optionally, alignment features634 may be included on paddles 632 of probes 408 to aid in determiningthe position and alignment of tips 636. The use of exemplary alignmentfeatures is discussed in U.S. Patent Application Publication No.2003/0013340 A1, which is incorporated by reference in its entiretyherein. As shown in FIGS. 4 and 5C, the tips 636 of probes 408 are thenmoved horizontally into contact with terminals 620 (step 506). Theterminals 620 may be pressed against the probes 408 such that the probesdeform, as shown in FIG. 5C. Alternatively, the movement may cause thetips of probes 408 to hop onto the surfaces of terminals 620.

It should be noted that the horizontal motion of step 506 may befollowed by some other type of motion. For example, a vertical or avertical up and down motion may be implemented to ensure that arelatively high force connection is established between the probes andthe wafer. Other or additional motions are possible, including furtherhorizontal motions.

Still referring to FIGS. 4 and 5A-5C, with the probes 408 in contactwith terminals 620, test signals are provide to the terminals throughprobe card 408, and response data generated by the die or dies to whichthe terminals are attached are sensed by certain of the probes 408 (step508). For example, such test signals may be generated by a tester 402.Once the testing is complete, the probes 408 and the terminals 620 arebrought out of contact with each other (step 510). Again, in a systemsuch as the one shown in FIG. 3, the chuck 414 moves the wafer 424 whilethe probe card 406 remains stationary. The path or directions of themovement used to remove probes 408 and terminals 620 from contact witheach other are not critical, and any paths or directions may be used.Nonlimiting examples of suitable paths include the reverse of themovement used to bring the wafer 424 into contact with the probes 408,simply moving the wafer in the “z” direction away from the probes, andmovement consistent with the type of device being tested and continueduse of the device. Controller 430 may be configured to move the wafer524 away from probes 508 using any of these or other ways, andcontroller 430 may do so by executing software and issuing controlsignals that control movement of chuck 414. Steps 502-510 may then berepeated until all or at least a portion of the dies on the wafer 424have been tested.

Terminals 620 may be any type of terminals, including without limitationflat terminals as shown in FIGS. 5A-5C as well as other shapedterminals, such as the spherically shaped terminals (e.g., solder balls)shown in FIGS. 6A-6C. FIGS. 6A-6C illustrate an exemplary application ofthe process shown in FIG. 4 where the terminals 720 on wafer 424 arespherically shaped. Otherwise, the process shown in FIGS. 6A-6C may begenerally similar to the process illustrated in FIGS. 5A-5C.

FIG. 7 illustrates an exemplary variation of the process shown in FIG.4. As shown in FIG. 7, after the wafer 424 is placed on the chuck, thechuck 414 is moved to position the wafer 424 in a position 1290 in whichthe terminals 620 on the wafer 424 are initially positioned 1290diagonally adjacent the probes 408. As also shown in FIG. 7, the chuck414 moves the wafer 424 diagonally into contact with the tips 636 ofprobes 408. Of course, terminals 620 may be any type of terminal,including without limitation spherically shaped terminals, such asterminals 720 shown in FIGS. 6A-6C.

FIGS. 8A and 8B illustrate another variation of the exemplary processesshown in FIG. 4. As shown in FIG. 8A, terminals 1020 of wafer 424 areinitially positioned below probes 408. Also as shown in FIG. 8A, asloped face or edge 638 of a probe tip 638 is aligned with a corner edge1022 of a terminal 1020. Then, as shown in FIG. 8B, chuck 414 moveswafer 424 upward into contact with probe tips 636. As the corner edge1022 of terminal 1020 comes into contact with and then slides along thesloped face or edge 638 of probe tip 636, the probe 408 is deflected asshown in FIG. 8B, creating a pressure contact between probe tips 636 andterminals 1020. Optionally, the distance by which tip 636 extends awayfrom paddle 632 may be made to be less than the height of terminals 1020from the surface of wafer 424. In this way, paddle 632 may act as astop, preventing tips 636 from contacting the surface of wafer 424.

FIGS. 9A and 9B illustrate a variation of the exemplary process shown inFIGS. 8A and 8B. As shown, wafer 424 in FIGS. 9A and 9B have roundedterminals 1120. As shown in FIG. 9A, terminals 1120 of wafer 424 arepositioned below probes 408. Preferably, a tip 636 of a probe 408 isaligned off center with a terminal 1120. Then, chuck 414 moves wafer 424upward into contact with probe tips 636, as shown in FIG. 9B. After aprobe tip 636 comes into contact with a terminal 1120, the probe tipslides along the periphery of the terminal, which may case the probe 408to deflect as shown in FIG. 9B, creating a pressure contact betweenprobe tips 636 and terminals 1120.

FIGS. 10A and 10B illustrate use of a probe 408 with two contact tips836 a, 836 b disposed on a paddle 832 of probe 408, which may beparticularly advantageous with rounded terminals 820. (FIG. 10A shows apartial bottom view of wafer 824 with a cut-away portion revealing thebottom of probe 408 and a portion of terminal 820.) Two (or more) tips836 a, 836 b may be particularly useful in “grabbing” rounded terminals820.

Each tip of each probe may have a plurality of contact features, andsuch contact features may be alternatingly used to contact a terminal.For example, probe 908 in FIGS. 11A and 11B has atruncated-pyramid-shaped tip 936, which has four faces 940 a-940 d (seeFIG. 11A) and four edges 942 a-942 d (see FIG. 11B). (In FIGS. 11A and11B, part of wafer 924 is cut away so that probe tip 936 and parts ofterminals 920 are visible.) As shown in FIG. 11A, any one of the faces940 a-940 d may make contact with a terminal 920. In the example shownin FIG. 11A, each face 940 a-940 d is a contact features. Faces 940a-940 d may optionally be rounded. Alternatively (or in addition), asshown in FIG. 11B, any one of edges 942 a-942 d may contact a terminal920. Thus, in FIG. 11B, edges 942 a-942 d are contact features. Ofcourse, the faces 940 a-940 d and the edges 942 a-942 d may makecontact, and each probe 908 may thus have eight contact features in theexample shown in FIGS. 11A and 11B. Other shaped tips may be used,including without limitation round tips.

FIG. 11C illustrates a process in which the time between cleaning probesmay be extended by using tips with multiple contact features, such astip 936 in FIGS. 11A and 11B. (As is known, debris may accumulate on thetips of probes as terminals are brought into and out of contact with theprobes.) As shown in FIG. 11C, one of a plurality of contact features ofa probe is selected at step 992. For example, edge 942 a of tip 936 inFIG. 9B may be selected. The testing of wafers then proceeds as in step994. The testing involves repeatedly moving a series of terminals intoand out of contact with the probe tips 936. Each time wafer terminalsare brought into contact with probes, the contact feature selected atstep 992 makes contact with the terminals. For example, if edge 942 a oftip 936 is selected at step 992, edge 942 a of tip 936 makes contactwith a terminal during step 994. After the terminals are brought intoand out of contact with probes a predetermined number of times, it isdetermined at step 996 whether all of the contact features of the probehave been used. The predetermined number of times may be any number; forexample, the predetermined number of times may be the number of contactsthis probe is to make between cleanings. Alternatively, rather thanperform step 994 for a predetermined number of contacts betweenterminals and the probes, step 994 may be performed until the contactresistance between the probes and the terminals exceeds a predeterminedthreshold. If the determination at step 996 is no, the process returnsto step 992 where a different one of the plurality of contact featuresis selected. For example, if edge 942 a was initially selected at step992, then edge 942 b may be selected. Thereafter, step 994 is repeated,but this time the newly selected contact feature (e.g., edge 942 b)makes the contacts with the wafer terminals at step 994. After thepredetermined number of contacts with terminals discussed above, step996 is repeated. If all of the contact features of the probe have nowbeen used as determined at step 996, the probe tips are cleaned in step998. For example, if all four edges 942 a-942 d of tip 936 have beenselected and used to make contact with terminals as determined at step996, the tip 936 is cleaned at step 992. Thereafter, the entire processis repeated as new wafers are tested.

FIG. 12 shows an exemplary test system 1200 in which probe card 406 iscapable of movement in the “x,” “y,” “z,” and “θ” directions. Of course,movement could be allowed in only one of those directions or only in acombination of two of those directions. (As with FIG. 3 above,directions in FIG. 12 are identified using an “x,” “y,” “z,” and “θ”coordinate system in which the “z” direction is the vertical direction(up or down) with respect to FIG. 12, the “x” direction is horizontallyinto or out of the page, the “y” direction is also horizontal but to theright or left in FIG. 12, and the “θ” direction is rotation. Thesedirections are for convenience, however, and are not limiting.)

The exemplary test system 1200 shown in FIG. 12 may be generally similarto the test system 400 illustrated in FIG. 3. The exemplary test system1200 shown in FIG. 12, however, includes a first track 1204 to which theprobe card 406 is attached with roller 1208, allowing the probe card 406to move in the “y” direction shown in FIG. 12. Tracks 1202 and rollers1206 allow the probe card 406 to move in the “x” direction, andtelescoping and rotary actuator 1210 allows the probe card 406 to movein the “z” and “θ” directions. Motors (not shown) or other actuators(not shown) effect such movements of the probe card. Controller 1230 maybe generally similar to controller 430 illustrated in FIG. 4 butmodified to issue control signals that move both the chuck 414 and theprobe card 406. (The chuck 414 may be similar to chuck 114 of FIG. 1.)Of course, the chuck 414 could be held stationary and only the probecard 406 moved. Modified to include movement of the probe card 406, theexemplary processes described herein may otherwise be implemented in asystem like that shown in FIG. 12.

FIGS. 13A-13C illustrate an exemplary process in which two contactfeatures 1334, 1338 on a probe 1308 are configured to make sequentialcontact with a terminal 422 of a wafer 424. That is, probes 1308 includea first contact feature 1338 and a second contact feature 1334. Thesecontact features 1334, 1338 are configured and situated on probes 1308so that a particular movement of wafer 424 by chuck 414 causes the firstcontact feature 1338 to contact terminal 422 and then the second contactfeature 1334 to contact terminals 422.

In the example shown in FIGS. 13A-13C, the first contact feature 1338 issomewhat elongate, and the second contact feature 1334 is pointed. Asshown in FIG. 13A, chuck 414 initially positions probes 1308 inproximity to terminals 422 of wafer 424. As shown in FIG. 13B, chuck 414then moves wafer 424 so that the first contact feature 1338 of eachprobe 1308 contacts a terminal 422. As shown in FIG. 13C, the chuck 414continues to move wafer 424, causing probes 1308 (which may be flexibleand/or resilient) to bend and the second contact feature 1334 to contactthe terminal 422. In the example shown in FIG. 13C, second contact 1334is pointed and pierces terminal 422, thus penetrating any oxide or othercontaminant on the surface of the terminal.

The particular configuration of contact features 1334, 1338 and themovement of wafer 424 shown in FIGS. 13A-13C is exemplary only. Anynumber, shape, and placement of contact features may be used on a probe,and any movement pattern may be implemented to cause a desired sequenceof contacts of the contact features on a probe with a terminal.

It should be apparent that, in all of the exemplary processes describedherein in which terminals are brought into contact with probe tips,after contact has been established, further movement of the terminals ispossible. For example, further up-and-down motions and/or furtherhorizontal back-and-forth motions of the terminals with respect to theprobe tips after the terminals have been brought into contact withprobes may reduce the contact electrical resistance between the probesand the terminals. Optionally, the contact resistance between the probesand the terminals may be monitored and movement of the chuckautomatically controlled so that the contact resistance is always lessthan a predetermined threshold.

Any of the processes described herein may be implemented in a testsystem, such as the exemplary test systems shown in FIG. 3 or 12. Asmentioned herein, the processes described herein may be implemented inother systems in which a probe is brought into contact with an object.Moreover, in any such system, the movements of the probe and/or theobject may be implemented in software stored in a memory and executed ona processor (e.g., as illustrated in FIG. 3). Alternatively, the controlof such movements may be implemented using electronic circuitry or acombination of software and circuitry.

Although the principles of the present invention have been illustratedand explained in the context of specific exemplary embodiments, variousmodifications can be made to the disclosed embodiments. For example, theforegoing descriptions refer to the components of the composite motionas “vertical” and “horizontal” movement components. The terms “vertical”and “horizontal” are relative, and other directional components may beused instead. As another example, the horizontal movement may includemovements other than linear movement. For example, the horizontalmovement may include a rotation in the horizontal (that is, “x, y”)plane. As yet another example, although the exemplary embodimentsdescribed herein probe a semiconductor device, the invention is not solimited. Rather, the invention may be used in any system in which aprobe is brought into contact with an object. Many other modificationsare possible.

1-20. (canceled)
 21. A method of testing electronic devices, the methodcomprising: obtaining a contactor device comprising a plurality ofelectrically conductive probes, one of the probes comprising a tipconfigured to contact a terminal of the electronic devices, the tipcomprising a plurality of different contact features; selecting one ofthe contact features of the tip not previously selected as a selectedcontact feature; contacting a terminal of the electronic devices withonly the selected contact feature; providing test signals through theone of the probes to one of the electronic devices; repeating thecontacting and the providing until determining that a predeterminedcondition regarding the selected contact feature has been reached; andafter determining that the predetermined condition regarding theselected contact feature has been reached, repeating the selecting, thecontacting, the providing, and the repeating the contacting and theproviding.
 22. The method of claim 21 further comprising repeating theselecting, the contacting, the providing, and the repeating thecontacting and the providing until determining that all of the contactfeatures of the tip have previously been selected.
 23. The method ofclaim 22 further comprising, after determining that all of the contactfeatures of the tip have previously been selected, cleaning the tip. 24.The method of claim 23, wherein the predetermined condition is apredetermined threshold number of contacts of the selected contactfeature with a terminal of the electronic devices.
 25. The method ofclaim 23, wherein the predetermined condition is a predeterminedthreshold contact resistance between the selected contact feature and aterminal of the electronic devices.
 26. The method of claim 23, whereineach of the plurality of contact features of the tip is a different edgeof the tip.
 27. The method of claim 23, wherein each of the plurality ofcontact features of the tip is a different face of the tip.
 28. Themethod of claim 23, wherein the tip comprises a truncated pyramid shape.29. The method of claim 28, wherein the truncated pyramid shapecomprises a plurality of faces.
 30. The method of claim 29, wherein eachof the plurality of contact features of the tip is a different one ofthe faces.
 31. The method of claim 29, wherein each of the plurality ofcontact features of the tip is a different one of an edge where adjacentones of the faces intersect.
 32. The method of claim 23, wherein theelectronic devices are semiconductor dies of a semiconductor wafer. 33.The method of claim 23, wherein the electronic devices are semiconductordies of a plurality of semiconductor wafers.
 34. The method of claim 21,wherein each of a plurality of the probes comprises a tip configured tocontact a terminal of the electronic device, and the tip comprising aplurality of different contact features.
 35. The method of claim 21,wherein: the contactor device is a probe card, the method furthercomprises coupling the probe card to a prober in which is enclosed amoveable chuck, and at least some of the electronic devices are disposedon the chuck.
 36. The method of claim 35, wherein the contactingcomprises moving the chuck such that the terminal of the electronicdevices contacts only the selected contact feature of the probe.